zfs [-?]

zfs create [-p] [-o property=value]... filesystem

zfs create [-ps] [-b blocksize] [-o property=value]... -V size volume

zfs destroy [-fnpRrv] filesystem|volume

zfs destroy [-dnpRrv] filesystem|volume@snap[%snap][,snap[%snap]]...

zfs snapshot [-r] [-o property=value]...
 filesystem@snapname|volume@snapname...

zfs rollback [-rRf] snapshot

zfs clone [-p] [-o property=value]... snapshot filesystem|volume

zfs promote clone-filesystem

zfs rename [-f] filesystem|volume|snapshot
 filesystem|volume|snapshot

zfs rename [-fp] filesystem|volume filesystem|volume

zfs rename -r snapshot snapshot

zfs list [-r|-d depth][-H][-o property[,property]...] [-t type[,type]...]
 [-s property]... [-S property]... [filesystem|volume|snapshot]...

zfs set property=value filesystem|volume|snapshot...

zfs get [-r|-d depth][-Hp][-o field[,field]...] [-t type[,type]...]
 [-s source[,source]...] all | property[,property]...
 filesystem|volume|snapshot...

zfs inherit [-r] property filesystem|volume|snapshot...

zfs upgrade [-v]

zfs upgrade [-r] [-V version] -a | filesystem

zfs userspace [-Hinp] [-o field[,field]...] [-s field]...
 [-S field]... [-t type[,type]...] filesystem|snapshot

zfs groupspace [-Hinp] [-o field[,field]...] [-s field]...
 [-S field]... [-t type[,type]...] filesystem|snapshot

zfs mount

zfs mount [-vO] [-o options] -a | filesystem

zfs unmount [-f] -a | filesystem|mountpoint

zfs share -a | filesystem

zfs unshare -a filesystem|mountpoint

zfs send [-DnPpRrv] [-[iI] snapshot] snapshot

zfs receive [-vnFu] filesystem|volume|snapshot

zfs receive [-vnFu] [-d|-e] filesystem

zfs allow filesystem|volume

zfs allow [-ldug] user|group[,user|group]...
 perm|@setname[,perm|@setname]... filesystem|volume

zfs allow [-ld] -e|everyone perm|@setname[,perm|@setname]...
 filesystem|volume

zfs allow -c perm|@setname[,perm|@setname]... filesystem|volume

zfs allow -s @setname perm|@setname[,perm|@setname]... filesystem|volume

zfs unallow [-rldug] user|group[,user|group]...
 [perm|@setname[,perm|@setname]...] filesystem|volume

zfs unallow [-rld] -e|everyone [perm|@setname[,perm|@setname]...]
 filesystem|volume

zfs unallow [-r] -c [perm|@setname[,perm|@setname]...] filesystem|volume

zfs unallow [-r] -s @setname [perm|@setname[,perm|@setname]...]
 filesystem|volume

zfs hold [-r] tag snapshot...

zfs holds [-r] snapshot...

zfs release [-r] tag snapshot...

zfs diff [-FHt] snapshot snapshot|filesystem

 DESCRIPTION

The zfs command configures ZFS datasets within a ZFS storage
pool, as described in zpool(1M). A dataset is identified by a unique path
within the ZFS namespace. For example:
pool/{filesystem,volume,snapshot}



where the maximum length of a dataset name is MAXNAMELEN (256 bytes).

A dataset can be one of the following:
file system

A ZFS dataset of type filesystem can be mounted within the standard
system namespace and behaves like other file systems. While ZFS file
systems are designed to be POSIX compliant, known issues exist that
prevent compliance in some cases. Applications that depend on standards
conformance might fail due to nonstandard behavior when checking file system
free space.


volume

A logical volume exported as a raw or block device. This type of dataset should
only be used under special circumstances. File systems are typically used in
most environments.


snapshot

A read-only version of a file system or volume at a given point in time. It is
specified as filesystem@name or volume@name.


 "ZFS File System Hierarchy"

A ZFS storage pool is a logical collection of devices that provide space
for datasets. A storage pool is also the root of the ZFS file system
hierarchy.

The root of the pool can be accessed as a file system, such as mounting and
unmounting, taking snapshots, and setting properties. The physical storage
characteristics, however, are managed by the zpool(1M) command.

See zpool(1M) for more information on creating and administering pools.
 "Snapshots"

A snapshot is a read-only copy of a file system or volume. Snapshots can be
created extremely quickly, and initially consume no additional space within the
pool. As data within the active dataset changes, the snapshot consumes more
data than would otherwise be shared with the active dataset.

Snapshots can have arbitrary names. Snapshots of volumes can be cloned or
rolled back, but cannot be accessed independently.

File system snapshots can be accessed under the .zfs/snapshot directory
in the root of the file system. Snapshots are automatically mounted on demand
and may be unmounted at regular intervals. The visibility of the .zfs
directory can be controlled by the snapdir property.
 "Clones"

A clone is a writable volume or file system whose initial contents are the same
as another dataset. As with snapshots, creating a clone is nearly
instantaneous, and initially consumes no additional space.

Clones can only be created from a snapshot. When a snapshot is cloned, it
creates an implicit dependency between the parent and child. Even though the
clone is created somewhere else in the dataset hierarchy, the original snapshot
cannot be destroyed as long as a clone exists. The origin property
exposes this dependency, and the destroy command lists any such
dependencies, if they exist.

The clone parent-child dependency relationship can be reversed by using the
promote subcommand. This causes the "origin" file system to become a
clone of the specified file system, which makes it possible to destroy the file
system that the clone was created from.
 "Mount Points"

Creating a ZFS file system is a simple operation, so the number of file
systems per system is likely to be numerous. To cope with this, ZFS
automatically manages mounting and unmounting file systems without the need to
edit the /etc/vfstab file. All automatically managed file systems are
mounted by ZFS at boot time.

By default, file systems are mounted under /path, where path
is the name of the file system in the ZFS namespace. Directories are
created and destroyed as needed.

A file system can also have a mount point set in the mountpoint property.
This directory is created as needed, and ZFS automatically mounts the
file system when the zfs mount -a command is invoked (without editing
/etc/vfstab). The mountpoint property can be inherited, so if
pool/home has a mount point of /export/stuff, then
pool/home/user automatically inherits a mount point of
/export/stuff/user.

A file system mountpoint property of none prevents the file system
from being mounted.

If needed, ZFS file systems can also be managed with traditional tools
(mount, umount, /etc/vfstab). If a file system's mount point
is set to legacy, ZFS makes no attempt to manage the file system,
and the administrator is responsible for mounting and unmounting the file
system.
 "Zones"

A ZFS file system can be added to a non-global zone by using the
zonecfg add fs subcommand. A ZFS file system that is added to
a non-global zone must have its mountpoint property set to legacy.

The physical properties of an added file system are controlled by the global
administrator. However, the zone administrator can create, modify, or destroy
files within the added file system, depending on how the file system is
mounted.

A dataset can also be delegated to a non-global zone by using the zonecfg
add dataset subcommand. You cannot delegate a dataset to one zone and the
children of the same dataset to another zone. The zone administrator can change
properties of the dataset or any of its children. However, the quota
property is controlled by the global administrator.

A ZFS volume can be added as a device to a non-global zone by using the
zonecfg add device subcommand. However, its physical properties can
be modified only by the global administrator.

For more information about zonecfg syntax, see zonecfg(1M).

After a dataset is delegated to a non-global zone, the zoned property is
automatically set. A zoned file system cannot be mounted in the global zone,
since the zone administrator might have to set the mount point to an
unacceptable value.

The global administrator can forcibly clear the zoned property, though
this should be done with extreme care. The global administrator should verify
that all the mount points are acceptable before clearing the property.
 "Native Properties"

Properties are divided into two types, native properties and user-defined (or
"user") properties. Native properties either export internal statistics or
control ZFS behavior. In addition, native properties are either editable
or read-only. User properties have no effect on ZFS behavior, but you can
use them to annotate datasets in a way that is meaningful in your environment.
For more information about user properties, see the "User Properties" section,
below.

Every dataset has a set of properties that export statistics about the dataset
as well as control various behaviors. Properties are inherited from the parent
unless overridden by the child. Some properties apply only to certain types of
datasets (file systems, volumes, or snapshots).

The values of numeric properties can be specified using human-readable suffixes
(for example, k, KB, M, Gb, and so forth, up to Z
for zettabyte). The following are all valid (and equal) specifications:
1536M, 1.5g, 1.50GB



The values of non-numeric properties are case sensitive and must be lowercase,
except for mountpoint, sharenfs, and sharesmb.

The following native properties consist of read-only statistics about the
dataset. These properties can be neither set, nor inherited. Native properties
apply to all dataset types unless otherwise noted.
available

The amount of space available to the dataset and all its children, assuming
that there is no other activity in the pool. Because space is shared within a
pool, availability can be limited by any number of factors, including physical
pool size, quotas, reservations, or other datasets within the pool.
This property can also be referred to by its shortened column name,
avail.


compressratio

For non-snapshots, the compression ratio achieved for the used
space of this dataset, expressed as a multiplier. The used
property includes descendant datasets, and, for clones, does not include
the space shared with the origin snapshot. For snapshots, the
compressratio is the same as the refcompressratio property.
Compression can be turned on by running: zfs set compression=on
dataset. The default value is off.


creation

The time this dataset was created.


clones

For snapshots, this property is a comma-separated list of filesystems or
volumes which are clones of this snapshot. The clones' origin property
is this snapshot. If the clones property is not empty, then this
snapshot can not be destroyed (even with the -r or -f options).


defer_destroy

This property is on if the snapshot has been marked for deferred destroy
by using the zfs destroy -d command. Otherwise, the property is
off.


logicalreferenced

The amount of space that is "logically" accessible by this dataset. See
the referenced property. The logical space ignores the effect of
the compression and copies properties, giving a quantity
closer to the amount of data that applications see. However, it does
include space consumed by metadata.
This property can also be referred to by its shortened column name,
lrefer.


logicalused

The amount of space that is "logically" consumed by this dataset and all
its descendents. See the used property. The logical space
ignores the effect of the compression and copies properties,
giving a quantity closer to the amount of data that applications see.
However, it does include space consumed by metadata.
This property can also be referred to by its shortened column name,
lused.


mounted

For file systems, indicates whether the file system is currently mounted. This
property can be either yes or no.


origin

For cloned file systems or volumes, the snapshot from which the clone was
created. See also the clones property.


referenced

The amount of data that is accessible by this dataset, which may or may not be
shared with other datasets in the pool. When a snapshot or clone is created, it
initially references the same amount of space as the file system or snapshot it
was created from, since its contents are identical.
This property can also be referred to by its shortened column name,
refer.


refcompressratio

The compression ratio achieved for the referenced space of this
dataset, expressed as a multiplier. See also the compressratio
property.


type

The type of dataset: filesystem, volume, or snapshot.


used

The amount of space consumed by this dataset and all its descendents. This is
the value that is checked against this dataset's quota and reservation. The
space used does not include this dataset's reservation, but does take into
account the reservations of any descendent datasets. The amount of space that a
dataset consumes from its parent, as well as the amount of space that are freed
if this dataset is recursively destroyed, is the greater of its space used and
its reservation.
When snapshots (see the "Snapshots" section) are created, their space is
initially shared between the snapshot and the file system, and possibly with
previous snapshots. As the file system changes, space that was previously
shared becomes unique to the snapshot, and counted in the snapshot's space
used. Additionally, deleting snapshots can increase the amount of space unique
to (and used by) other snapshots.
The amount of space used, available, or referenced does not take into account
pending changes. Pending changes are generally accounted for within a few
seconds. Committing a change to a disk using fsync(3c) or O_SYNC
does not necessarily guarantee that the space usage information is updated
immediately.


usedby*

The usedby* properties decompose the used properties into the
various reasons that space is used. Specifically, used =
usedbychildren + usedbydataset + usedbyrefreservation +,
usedbysnapshots. These properties are only available for datasets created
on zpool "version 13" pools.


usedbychildren

The amount of space used by children of this dataset, which would be freed if
all the dataset's children were destroyed.


usedbydataset

The amount of space used by this dataset itself, which would be freed if the
dataset were destroyed (after first removing any refreservation and
destroying any necessary snapshots or descendents).


usedbyrefreservation

The amount of space used by a refreservation set on this dataset, which
would be freed if the refreservation was removed.


usedbysnapshots

The amount of space consumed by snapshots of this dataset. In particular, it is
the amount of space that would be freed if all of this dataset's snapshots were
destroyed. Note that this is not simply the sum of the snapshots' used
properties because space can be shared by multiple snapshots.


userused@user

The amount of space consumed by the specified user in this dataset. Space is
charged to the owner of each file, as displayed by ls -l. The
amount of space charged is displayed by du and ls -s. See the
zfs userspace subcommand for more information.
Unprivileged users can access only their own space usage. The root user, or a
user who has been granted the userused privilege with zfs allow,
can access everyone's usage.
The userused@... properties are not displayed by zfs get all. The
user's name must be appended after the @ symbol, using one of the
following forms:


POSIX name (for example, joe)



POSIX numeric ID (for example, 789)



SID name (for example, joe.smith@mydomain)



SID numeric ID (for example, S-1-123-456-789)



userrefs

This property is set to the number of user holds on this snapshot. User holds
are set by using the zfs hold command.


groupused@group

The amount of space consumed by the specified group in this dataset. Space is
charged to the group of each file, as displayed by ls -l. See the
userused@user property for more information.
Unprivileged users can only access their own groups' space usage. The root
user, or a user who has been granted the groupused privilege with zfs
allow, can access all groups' usage.


volblocksize=blocksize

For volumes, specifies the block size of the volume. The blocksize cannot
be changed once the volume has been written, so it should be set at volume
creation time. The default blocksize for volumes is 8 Kbytes. Any power
of 2 from 512 bytes to 128 Kbytes is valid.
This property can also be referred to by its shortened column name,
volblock.


written

The amount of referenced space written to this dataset since the
previous snapshot.


written@snapshot

The amount of referenced space written to this dataset since the
specified snapshot. This is the space that is referenced by this dataset
but was not referenced by the specified snapshot.
The snapshot may be specified as a short snapshot name (just the part
after the @), in which case it will be interpreted as a snapshot in
the same filesystem as this dataset.
The snapshot be a full snapshot name (filesystem@snapshot),
which for clones may be a snapshot in the origin's filesystem (or the origin
of the origin's filesystem, etc).



The following native properties can be used to change the behavior of a
ZFS dataset.
aclinherit=discard | noallow | restricted |
passthrough | passthrough-x

Controls how ACL entries are inherited when files and directories are
created. A file system with an aclinherit property of discard does
not inherit any ACL entries. A file system with an aclinherit
property value of noallow only inherits inheritable ACL entries
that specify "deny" permissions. The property value restricted (the
default) removes the write_acl and write_owner permissions when the
ACL entry is inherited. A file system with an aclinherit property
value of passthrough inherits all inheritable ACL entries without
any modifications made to the ACL entries when they are inherited. A file
system with an aclinherit property value of passthrough-x has the
same meaning as passthrough, except that the owner@, group@,
and everyone@ ACEs inherit the execute permission only if the file
creation mode also requests the execute bit.
When the property value is set to passthrough, files are created with a
mode determined by the inheritable ACEs. If no inheritable ACEs
exist that affect the mode, then the mode is set in accordance to the requested
mode from the application.


aclmode=discard | groupmask | passthrough | restricted

Controls how an ACL is modified during chmod(2). A file system with
an aclmode property of discard (the default) deletes all ACL
entries that do not represent the mode of the file. An aclmode property
of groupmask reduces permissions granted in all ALLOW entries found
in the ACL such that they are no greater than the group permissions
specified by chmod(2). A file system with an aclmode property of
passthrough indicates that no changes are made to the ACL other
than creating or updating the necessary ACL entries to represent the new
mode of the file or directory. An aclmode property of restricted
will cause the chmod(2) operation to return an error when used on any
file or directory which has a non-trivial ACL whose entries can not be
represented by a mode. chmod(2) is required to change the set user ID,
set group ID, or sticky bits on a file or directory, as they do not have
equivalent ACL entries. In order to use chmod(2) on a file or
directory with a non-trivial ACL when aclmode is set to
restricted, you must first remove all ACL entries which do not
represent the current mode.


atime=on | off

Controls whether the access time for files is updated when they are read.
Turning this property off avoids producing write traffic when reading files and
can result in significant performance gains, though it might confuse mailers
and other similar utilities. The default value is on.


canmount=on | off | noauto

If this property is set to off, the file system cannot be mounted, and is
ignored by zfs mount -a. Setting this property to off is similar to
setting the mountpoint property to none, except that the dataset
still has a normal mountpoint property, which can be inherited. Setting
this property to off allows datasets to be used solely as a mechanism to
inherit properties. One example of setting canmount=off is to have
two datasets with the same mountpoint, so that the children of both
datasets appear in the same directory, but might have different inherited
characteristics.
When the noauto option is set, a dataset can only be mounted and
unmounted explicitly. The dataset is not mounted automatically when the dataset
is created or imported, nor is it mounted by the zfs mount -a command or
unmounted by the zfs unmount -a command.
This property is not inherited.


checksum=on | off | fletcher2 | fletcher4 |
sha256 | noparity 

Controls the checksum used to verify data integrity. The default value is
on, which automatically selects an appropriate algorithm (currently,
fletcher4, but this may change in future releases). The value off
disables integrity checking on user data. The value noparity not only
disables integrity but also disables maintaining parity for user data. This
setting is used internally by a dump device residing on a RAID-Z pool and should
not be used by any other dataset. Disabling checksums is NOT a recommended
practice.
Changing this property affects only newly-written data.


compression=on | off | lzjb | gzip |
gzip-N | zle | lz4

Controls the compression algorithm used for this dataset. The lzjb
compression algorithm is optimized for performance while providing decent data
compression. Setting compression to on uses the lzjb compression
algorithm. The gzip compression algorithm uses the same compression as
the gzip(1) command. You can specify the gzip level by using the
value gzip-N where N is an integer from 1 (fastest) to 9
(best compression ratio). Currently, gzip is equivalent to gzip-6
(which is also the default for gzip(1)). The zle compression
algorithm compresses runs of zeros.
The lz4 compression algorithm is a high-performance replacement
for the lzjb algorithm. It features significantly faster
compression and decompression, as well as a moderately higher
compression ratio than lzjb, but can only be used on pools with
the lz4_compress feature set to enabled. See
zpool-features(5) for details on ZFS feature flags and the
lz4_compress feature.
This property can also be referred to by its shortened column name
compress. Changing this property affects only newly-written data.


copies=1 | 2 | 3

Controls the number of copies of data stored for this dataset. These copies are
in addition to any redundancy provided by the pool, for example, mirroring or
RAID-Z. The copies are stored on different disks, if possible. The space used
by multiple copies is charged to the associated file and dataset, changing the
used property and counting against quotas and reservations.
Changing this property only affects newly-written data. Therefore, set this
property at file system creation time by using the -o
copies=N option.


devices=on | off

Controls whether device nodes can be opened on this file system. The default
value is on.


exec=on | off

Controls whether processes can be executed from within this file system. The
default value is on.


mountpoint=path | none | legacy

Controls the mount point used for this file system. See the "Mount Points"
section for more information on how this property is used.
When the mountpoint property is changed for a file system, the file
system and any children that inherit the mount point are unmounted. If the new
value is legacy, then they remain unmounted. Otherwise, they are
automatically remounted in the new location if the property was previously
legacy or none, or if they were mounted before the property was
changed. In addition, any shared file systems are unshared and shared in the
new location.


nbmand=on | off

Controls whether the file system should be mounted with nbmand (Non
Blocking mandatory locks). This is used for CIFS clients. Changes to this
property only take effect when the file system is umounted and remounted. See
mount(1M) for more information on nbmand mounts.


primarycache=all | none | metadata

Controls what is cached in the primary cache (ARC). If this property is set to
all, then both user data and metadata is cached. If this property is set
to none, then neither user data nor metadata is cached. If this property
is set to metadata, then only metadata is cached. The default value is
all.


quota=size | none

Limits the amount of space a dataset and its descendents can consume. This
property enforces a hard limit on the amount of space used. This includes all
space consumed by descendents, including file systems and snapshots. Setting a
quota on a descendent of a dataset that already has a quota does not override
the ancestor's quota, but rather imposes an additional limit.
Quotas cannot be set on volumes, as the volsize property acts as an
implicit quota.


userquota@user=size | none

Limits the amount of space consumed by the specified user. User space
consumption is identified by the userspace@user property.
Enforcement of user quotas may be delayed by several seconds. This delay means
that a user might exceed their quota before the system notices that they are
over quota and begins to refuse additional writes with the EDQUOT error
message . See the zfs userspace subcommand for more information.
Unprivileged users can only access their own groups' space usage. The root
user, or a user who has been granted the userquota privilege with zfs
allow, can get and set everyone's quota.
This property is not available on volumes, on file systems before version 4, or
on pools before version 15. The userquota@... properties are not
displayed by zfs get all. The user's name must be appended after the
@ symbol, using one of the following forms:


POSIX name (for example, joe)



POSIX numeric ID (for example, 789)



SID name (for example, joe.smith@mydomain)



SID numeric ID (for example, S-1-123-456-789)



groupquota@group=size | none

Limits the amount of space consumed by the specified group. Group space
consumption is identified by the userquota@user property.
Unprivileged users can access only their own groups' space usage. The root
user, or a user who has been granted the groupquota privilege with zfs
allow, can get and set all groups' quotas.


readonly=on | off

Controls whether this dataset can be modified. The default value is off.
This property can also be referred to by its shortened column name,
rdonly.


recordsize=size

Specifies a suggested block size for files in the file system. This property is
designed solely for use with database workloads that access files in fixed-size
records. ZFS automatically tunes block sizes according to internal
algorithms optimized for typical access patterns.
For databases that create very large files but access them in small random
chunks, these algorithms may be suboptimal. Specifying a recordsize
greater than or equal to the record size of the database can result in
significant performance gains. Use of this property for general purpose file
systems is strongly discouraged, and may adversely affect performance.
The size specified must be a power of two greater than or equal to 512 and less
than or equal to 128 Kbytes.
Changing the file system's recordsize affects only files created
afterward; existing files are unaffected.
This property can also be referred to by its shortened column name,
recsize.


refquota=size | none

Limits the amount of space a dataset can consume. This property enforces a hard
limit on the amount of space used. This hard limit does not include space used
by descendents, including file systems and snapshots.


refreservation=size | none

The minimum amount of space guaranteed to a dataset, not including its
descendents. When the amount of space used is below this value, the dataset is
treated as if it were taking up the amount of space specified by
refreservation. The refreservation reservation is accounted for in
the parent datasets' space used, and counts against the parent datasets' quotas
and reservations.
If refreservation is set, a snapshot is only allowed if there is enough
free pool space outside of this reservation to accommodate the current number
of "referenced" bytes in the dataset.
This property can also be referred to by its shortened column name,
refreserv.


reservation=size | none

The minimum amount of space guaranteed to a dataset and its descendents. When
the amount of space used is below this value, the dataset is treated as if it
were taking up the amount of space specified by its reservation. Reservations
are accounted for in the parent datasets' space used, and count against the
parent datasets' quotas and reservations.
This property can also be referred to by its shortened column name,
reserv.


secondarycache=all | none | metadata

Controls what is cached in the secondary cache (L2ARC). If this property is set
to all, then both user data and metadata is cached. If this property is
set to none, then neither user data nor metadata is cached. If this
property is set to metadata, then only metadata is cached. The default
value is all.


setuid=on | off

Controls whether the set-UID bit is respected for the file system. The
default value is on.


shareiscsi=on | off

Like the sharenfs property, shareiscsi indicates whether a
ZFS volume is exported as an iSCSI target. The acceptable values
for this property are on, off, and type=disk. The default
value is off. In the future, other target types might be supported. For
example, tape.
You might want to set shareiscsi=on for a file system so that all
ZFS volumes within the file system are shared by default. However,
setting this property on a file system has no direct effect.


sharesmb=on | off | opts

Controls whether the file system is shared by using the Solaris CIFS
service, and what options are to be used. A file system with the sharesmb
property set to off is managed through traditional tools such as
sharemgr(1M). Otherwise, the file system is automatically shared and
unshared with the zfs share and zfs unshare commands. If the
property is set to on, the sharemgr(1M) command is invoked with no
options. Otherwise, the sharemgr(1M) command is invoked with options
equivalent to the contents of this property.
Because SMB shares requires a resource name, a unique resource name is
constructed from the dataset name. The constructed name is a copy of the
dataset name except that the characters in the dataset name, which would be
illegal in the resource name, are replaced with underscore (_)
characters. A pseudo property "name" is also supported that allows you to
replace the data set name with a specified name. The specified name is then
used to replace the prefix dataset in the case of inheritance. For example, if
the dataset data/home/john is set to name=john, then
data/home/john has a resource name of john. If a child dataset of
data/home/john/backups, it has a resource name of john_backups.
When SMB shares are created, the SMB share name appears as an entry in the
.zfs/shares directory. You can use the ls or chmod command
to display the share-level ACLs on the entries in this directory.
When the sharesmb property is changed for a dataset, the dataset and any
children inheriting the property are re-shared with the new options, only if
the property was previously set to off, or if they were shared before the
property was changed. If the new property is set to off, the file systems
are unshared.


sharenfs=on | off | opts

Controls whether the file system is shared via NFS, and what options are
used. A file system with a sharenfs property of off is managed
through traditional tools such as share(1M), unshare(1M), and
dfstab(4). Otherwise, the file system is automatically shared and
unshared with the zfs share and zfs unshare commands. If the
property is set to on, the share(1M) command is invoked with no
options. Otherwise, the share(1M) command is invoked with options
equivalent to the contents of this property.
When the sharenfs property is changed for a dataset, the dataset and any
children inheriting the property are re-shared with the new options, only if
the property was previously off, or if they were shared before the
property was changed. If the new property is off, the file systems are
unshared.


logbias = latency | throughput

Provide a hint to ZFS about handling of synchronous requests in this dataset.
If logbias is set to latency (the default), ZFS will use pool log
devices (if configured) to handle the requests at low latency. If logbias
is set to throughput, ZFS will not use configured pool log devices. ZFS
will instead optimize synchronous operations for global pool throughput and
efficient use of resources.


snapdir=hidden | visible

Controls whether the .zfs directory is hidden or visible in the root of
the file system as discussed in the "Snapshots" section. The default value is
hidden.


sync=default | always | disabled

Controls the behavior of synchronous requests (e.g. fsync, O_DSYNC).
default is the POSIX specified behavior of ensuring all synchronous
requests are written to stable storage and all devices are flushed to ensure
data is not cached by device controllers (this is the default). always
causes every file system transaction to be written and flushed before its
system call returns. This has a large performance penalty. disabled
disables synchronous requests. File system transactions are only committed to
stable storage periodically. This option will give the highest performance.
However, it is very dangerous as ZFS would be ignoring the synchronous
transaction demands of applications such as databases or NFS. Administrators
should only use this option when the risks are understood.


version=1 | 2 | current

The on-disk version of this file system, which is independent of the pool
version. This property can only be set to later supported versions. See the
zfs upgrade command.


volsize=size

For volumes, specifies the logical size of the volume. By default, creating a
volume establishes a reservation of equal size. For storage pools with a
version number of 9 or higher, a refreservation is set instead. Any
changes to volsize are reflected in an equivalent change to the
reservation (or refreservation). The volsize can only be set to a
multiple of volblocksize, and cannot be zero.
The reservation is kept equal to the volume's logical size to prevent
unexpected behavior for consumers. Without the reservation, the volume could
run out of space, resulting in undefined behavior or data corruption, depending
on how the volume is used. These effects can also occur when the volume size is
changed while it is in use (particularly when shrinking the size). Extreme care
should be used when adjusting the volume size.
Though not recommended, a "sparse volume" (also known as "thin provisioning")
can be created by specifying the -s option to the zfs create -V
command, or by changing the reservation after the volume has been created. A
"sparse volume" is a volume where the reservation is less then the volume size.
Consequently, writes to a sparse volume can fail with ENOSPC when the
pool is low on space. For a sparse volume, changes to volsize are not
reflected in the reservation.


vscan=on | off

Controls whether regular files should be scanned for viruses when a file is
opened and closed. In addition to enabling this property, the virus scan
service must also be enabled for virus scanning to occur. The default value is
off.


xattr=on | off

Controls whether extended attributes are enabled for this file system. The
default value is on.


zoned=on | off

Controls whether the dataset is managed from a non-global zone. See the "Zones"
section for more information. The default value is off.



The following three properties cannot be changed after the file system is
created, and therefore, should be set when the file system is created. If the
properties are not set with the zfs create or zpool create
commands, these properties are inherited from the parent dataset. If the parent
dataset lacks these properties due to having been created prior to these
features being supported, the new file system will have the default values for
these properties.
casesensitivity=sensitive | insensitive | mixed

Indicates whether the file name matching algorithm used by the file system
should be case-sensitive, case-insensitive, or allow a combination of both
styles of matching. The default value for the casesensitivity property is
sensitive. Traditionally, UNIX and POSIX file systems have case-sensitive
file names.
The mixed value for the casesensitivity property indicates that the
file system can support requests for both case-sensitive and case-insensitive
matching behavior. Currently, case-insensitive matching behavior on a file
system that supports mixed behavior is limited to the Solaris CIFS server
product. For more information about the mixed value behavior, see the
Solaris ZFS Administration Guide.


normalization = none | formC | formD | formKC
| formKD

Indicates whether the file system should perform a unicode normalization
of file names whenever two file names are compared, and which normalization
algorithm should be used. File names are always stored unmodified, names are
normalized as part of any comparison process. If this property is set to a
legal value other than none, and the utf8only property was left
unspecified, the utf8only property is automatically set to on. The
default value of the normalization property is none. This property
cannot be changed after the file system is created.


utf8only=on | off

Indicates whether the file system should reject file names that include
characters that are not present in the UTF-8 character code set. If this
property is explicitly set to off, the normalization property must either
not be explicitly set or be set to none. The default value for the
utf8only property is off. This property cannot be changed after the
file system is created.



The casesensitivity, normalization, and utf8only properties
are also new permissions that can be assigned to non-privileged users by using
the ZFS delegated administration feature.
 "Temporary Mount Point Properties"

When a file system is mounted, either through mount(1M) for legacy mounts
or the zfs mount command for normal file systems, its mount options are
set according to its properties. The correlation between properties and mount
options is as follows:
 PROPERTY MOUNT OPTION
 devices devices/nodevices
 exec exec/noexec
 readonly ro/rw
 setuid setuid/nosetuid
 xattr xattr/noxattr



In addition, these options can be set on a per-mount basis using the -o
option, without affecting the property that is stored on disk. The values
specified on the command line override the values stored in the dataset. The
-nosuid option is an alias for nodevices,nosetuid. These properties
are reported as "temporary" by the zfs get command. If the properties are
changed while the dataset is mounted, the new setting overrides any temporary
settings.
 "User Properties"

In addition to the standard native properties, ZFS supports arbitrary
user properties. User properties have no effect on ZFS behavior, but
applications or administrators can use them to annotate datasets (file systems,
volumes, and snapshots).

User property names must contain a colon (:) character to distinguish
them from native properties. They may contain lowercase letters, numbers, and
the following punctuation characters: colon (:), dash (-), period
(.), and underscore (_). The expected convention is that the
property name is divided into two portions such as
module:property, but this namespace is not enforced by
ZFS. User property names can be at most 256 characters, and cannot begin
with a dash (-).

When making programmatic use of user properties, it is strongly suggested to
use a reversed DNS domain name for the module component of property
names to reduce the chance that two independently-developed packages use the
same property name for different purposes. Property names beginning with
com.sun. are reserved for use by Sun Microsystems.

The values of user properties are arbitrary strings, are always inherited, and
are never validated. All of the commands that operate on properties (zfs
list, zfs get, zfs set, and so forth) can be used to manipulate
both native properties and user properties. Use the zfs inherit command
to clear a user property . If the property is not defined in any parent
dataset, it is removed entirely. Property values are limited to 1024
characters.
 "ZFS Volumes as Swap or Dump Devices"

During an initial installation a swap device and dump device are created on
ZFS volumes in the ZFS root pool. By default, the swap area size is
based on 1/2 the size of physical memory up to 2 Gbytes. The size of the dump
device depends on the kernel's requirements at installation time. Separate
ZFS volumes must be used for the swap area and dump devices. Do not swap
to a file on a ZFS file system. A ZFS swap file configuration is
not supported.

If you need to change your swap area or dump device after the system is
installed or upgraded, use the swap(1M) and dumpadm(1M) commands.
If you need to change the size of your swap area or dump device, see the
Solaris ZFS Administration Guide.
 SUBCOMMANDS

All subcommands that modify state are logged persistently to the pool in their
original form.
zfs ?

Displays a help message.


zfs create [-p] [-o property=value]...
filesystem

Creates a new ZFS file system. The file system is automatically mounted
according to the mountpoint property inherited from the parent.
-p

Creates all the non-existing parent datasets. Datasets created in this manner
are automatically mounted according to the mountpoint property inherited
from their parent. Any property specified on the command line using the
-o option is ignored. If the target filesystem already exists, the
operation completes successfully.


-o property=value

Sets the specified property as if the command zfs set
property=value was invoked at the same time the dataset was
created. Any editable ZFS property can also be set at creation time.
Multiple -o options can be specified. An error results if the same
property is specified in multiple -o options.




zfs create [-ps] [-b blocksize] [-o
property=value]... -V size volume

Creates a volume of the given size. The volume is exported as a block device in
/dev/zvol/{dsk,rdsk}/path, where path is the name of the
volume in the ZFS namespace. The size represents the logical size as
exported by the device. By default, a reservation of equal size is created.
size is automatically rounded up to the nearest 128 Kbytes to ensure that
the volume has an integral number of blocks regardless of blocksize.
-p

Creates all the non-existing parent datasets. Datasets created in this manner
are automatically mounted according to the mountpoint property inherited
from their parent. Any property specified on the command line using the
-o option is ignored. If the target filesystem already exists, the
operation completes successfully.


-s

Creates a sparse volume with no reservation. See volsize in the Native
Properties section for more information about sparse volumes.


-o property=value

Sets the specified property as if the zfs set property=value
command was invoked at the same time the dataset was created. Any editable
ZFS property can also be set at creation time. Multiple -o options
can be specified. An error results if the same property is specified in
multiple -o options.


-b blocksize

Equivalent to -o volblocksize=blocksize. If this option is
specified in conjunction with -o volblocksize, the resulting
behavior is undefined.




zfs destroy [-fnpRrv] filesystem|volume

Destroys the given dataset. By default, the command unshares any file systems
that are currently shared, unmounts any file systems that are currently
mounted, and refuses to destroy a dataset that has active dependents (children
or clones).
-r

Recursively destroy all children.


-R

Recursively destroy all dependents, including cloned file systems outside the
target hierarchy.


-f

Force an unmount of any file systems using the unmount -f command. This
option has no effect on non-file systems or unmounted file systems.


-n

Do a dry-run ("No-op") deletion. No data will be deleted. This is
useful in conjunction with the -v or -p flags to determine what
data would be deleted.


-p

Print machine-parsable verbose information about the deleted data.


-v

Print verbose information about the deleted data.

Extreme care should be taken when applying either the -r or the -R
options, as they can destroy large portions of a pool and cause unexpected
behavior for mounted file systems in use.


zfs destroy [-dnpRrv] filesystem|volume@snap[%snap][,snap[%snap]]...

The given snapshots are destroyed immediately if and only if the zfs
destroy command without the -d option would have destroyed it. Such
immediate destruction would occur, for example, if the snapshot had no clones
and the user-initiated reference count were zero.
If a snapshot does not qualify for immediate destruction, it is marked for
deferred deletion. In this state, it exists as a usable, visible snapshot until
both of the preconditions listed above are met, at which point it is destroyed.
An inclusive range of snapshots may be specified by separating the
first and last snapshots with a percent sign.
The first and/or last snapshots may be left blank, in which case the
filesystem's oldest or newest snapshot will be implied.
Multiple snapshots
(or ranges of snapshots) of the same filesystem or volume may be specified
in a comma-separated list of snapshots.
Only the snapshot's short name (the
part after the @) should be specified when using a range or
comma-separated list to identify multiple snapshots.
-d

Defer snapshot deletion.


-r

Destroy (or mark for deferred deletion) all snapshots with this name in
descendent file systems.


-R

Recursively destroy all clones of these snapshots, including the clones,
snapshots, and children. If this flag is specified, the -d flag will
have no effect.


-n

Do a dry-run ("No-op") deletion. No data will be deleted. This is
useful in conjunction with the -v or -p flags to determine what
data would be deleted.


-p

Print machine-parsable verbose information about the deleted data.


-v

Print verbose information about the deleted data.


Extreme care should be taken when applying either the -r or the -R
options, as they can destroy large portions of a pool and cause unexpected
behavior for mounted file systems in use.


zfs snapshot [-r] [-o property=value]...
filesystem@snapname|volume@snapname...

Creates snapshots with the given names. All previous modifications by
successful system calls to the file system are part of the snapshots.
Snapshots are taken atomically, so that all snapshots correspond to the same
moment in time. See the "Snapshots" section for details.
-r

Recursively create snapshots of all descendent datasets


-o property=value

Sets the specified property; see zfs create for details.




zfs rollback [-rRf] snapshot

Roll back the given dataset to a previous snapshot. When a dataset is rolled
back, all data that has changed since the snapshot is discarded, and the
dataset reverts to the state at the time of the snapshot. By default, the
command refuses to roll back to a snapshot other than the most recent one. In
order to do so, all intermediate snapshots must be destroyed by specifying the
-r option.
The -rR options do not recursively destroy the child snapshots of a
recursive snapshot. Only the top-level recursive snapshot is destroyed by
either of these options. To completely roll back a recursive snapshot, you must
rollback the individual child snapshots.
-r

Recursively destroy any snapshots more recent than the one specified.


-R

Recursively destroy any more recent snapshots, as well as any clones of those
snapshots.


-f

Used with the -R option to force an unmount of any clone file systems
that are to be destroyed.




zfs clone [-p] [-o property=value]...
snapshot filesystem|volume

Creates a clone of the given snapshot. See the "Clones" section for details.
The target dataset can be located anywhere in the ZFS hierarchy, and is
created as the same type as the original.
-p

Creates all the non-existing parent datasets. Datasets created in this manner
are automatically mounted according to the mountpoint property inherited
from their parent. If the target filesystem or volume already exists, the
operation completes successfully.


-o property=value

Sets the specified property; see zfs create for details.




zfs promote clone-filesystem

Promotes a clone file system to no longer be dependent on its "origin"
snapshot. This makes it possible to destroy the file system that the clone was
created from. The clone parent-child dependency relationship is reversed, so
that the origin file system becomes a clone of the specified file system.
The snapshot that was cloned, and any snapshots previous to this snapshot, are
now owned by the promoted clone. The space they use moves from the origin file
system to the promoted clone, so enough space must be available to accommodate
these snapshots. No new space is consumed by this operation, but the space
accounting is adjusted. The promoted clone must not have any conflicting
snapshot names of its own. The rename subcommand can be used to rename
any conflicting snapshots.


zfs rename [-f] filesystem|volume|snapshot

filesystem|volume|snapshot

zfs rename [-fp] filesystem|volume
filesystem|volume

Renames the given dataset. The new target can be located anywhere in the
ZFS hierarchy, with the exception of snapshots. Snapshots can only be
renamed within the parent file system or volume. When renaming a snapshot, the
parent file system of the snapshot does not need to be specified as part of the
second argument. Renamed file systems can inherit new mount points, in which
case they are unmounted and remounted at the new mount point.
-p

Creates all the nonexistent parent datasets. Datasets created in this manner
are automatically mounted according to the mountpoint property inherited
from their parent.


-f

Force unmount any filesystems that need to be unmounted in the process.




zfs rename -r snapshot snapshot

Recursively rename the snapshots of all descendent datasets. Snapshots are the
only dataset that can be renamed recursively.


zfs list [-r|-d depth] [-H] [-o
property[,property]...] [ -t type[,type]...] [ -s
property ]... [ -S property ]...
[filesystem|volume|snapshot]...

Lists the property information for the given datasets in tabular form. If
specified, you can list property information by the absolute pathname or the
relative pathname. By default, all file systems and volumes are displayed.
Snapshots are displayed if the listsnaps property is on (the
default is off) . The following fields are displayed,
name,used,available,referenced,mountpoint.
-H

Used for scripting mode. Do not print headers and separate fields by a single
tab instead of arbitrary white space.


-r

Recursively display any children of the dataset on the command line.


-d depth

Recursively display any children of the dataset, limiting the recursion to
depth. A depth of 1 will display only the dataset and its direct
children.


-o property

A comma-separated list of properties to display. The property must be:


One of the properties described in the "Native Properties" section



A user property



The value name to display the dataset name



The value space to display space usage properties on file systems and
volumes. This is a shortcut for specifying -o
name,avail,used,usedsnap,usedds,usedrefreserv,usedchild -t
filesystem,volume syntax.



-s property

A property for sorting the output by column in ascending order based on the
value of the property. The property must be one of the properties described in
the "Properties" section, or the special value name to sort by the
dataset name. Multiple properties can be specified at one time using multiple
-s property options. Multiple -s options are evaluated from left to
right in decreasing order of importance.
The following is a list of sorting criteria:


Numeric types sort in numeric order.



String types sort in alphabetical order.



Types inappropriate for a row sort that row to the literal bottom, regardless
of the specified ordering.



If no sorting options are specified the existing behavior of zfs list is
preserved.



-S property

Same as the -s option, but sorts by property in descending order.


-t type

A comma-separated list of types to display, where type is one of
filesystem, snapshot , volume, or all. For example,
specifying -t snapshot displays only snapshots.




zfs set property=value
filesystem|volume|snapshot...

Sets the property to the given value for each dataset. Only some properties can
be edited. See the "Properties" section for more information on what properties
can be set and acceptable values. Numeric values can be specified as exact
values, or in a human-readable form with a suffix of B, K, M,
G, T, P, E, Z (for bytes, kilobytes, megabytes,
gigabytes, terabytes, petabytes, exabytes, or zettabytes, respectively). User
properties can be set on snapshots. For more information, see the "User
Properties" section.


zfs get [-r|-d depth] [-Hp] [-o
field[,field]... [-t type[,type]...] [-s source[,source]... all |
property[,property]... filesystem|volume|snapshot...

Displays properties for the given datasets. If no datasets are specified, then
the command displays properties for all datasets on the system. For each
property, the following columns are displayed:
 name Dataset name
 property Property name
 value Property value
 source Property source. Can either be local, default,
 temporary, inherited, or none (-).


All columns are displayed by default, though this can be controlled by using
the -o option. This command takes a comma-separated list of properties as
described in the "Native Properties" and "User Properties" sections.
The special value all can be used to display all properties that apply to
the given dataset's type (filesystem, volume, or snapshot).
-r

Recursively display properties for any children.


-d depth

Recursively display any children of the dataset, limiting the recursion to
depth. A depth of 1 will display only the dataset and its direct
children.


-H

Display output in a form more easily parsed by scripts. Any headers are
omitted, and fields are explicitly separated by a single tab instead of an
arbitrary amount of space.


-o field

A comma-separated list of columns to display. name,property,value,source
is the default value.


-s source

A comma-separated list of sources to display. Those properties coming from a
source other than those in this list are ignored. Each source must be one of
the following: local,default,inherited,temporary,none. The default value
is all sources.


-p

Display numbers in parseable (exact) values.




zfs inherit [-r] property
filesystem|volume|snapshot...

Clears the specified property, causing it to be inherited from an ancestor. If
no ancestor has the property set, then the default value is used. See the
"Properties" section for a listing of default values, and details on which
properties can be inherited.
-r

Recursively inherit the given property for all children.




zfs upgrade [-v]

Displays a list of file systems that are not the most recent version.


zfs upgrade [-r] [-V version] [-a |
filesystem]

Upgrades file systems to a new on-disk version. Once this is done, the file
systems will no longer be accessible on systems running older versions of the
software. zfs send streams generated from new snapshots of these file
systems cannot be accessed on systems running older versions of the software.
In general, the file system version is independent of the pool version. See
zpool(1M) for information on the zpool upgrade command.
In some cases, the file system version and the pool version are interrelated
and the pool version must be upgraded before the file system version can be
upgraded.
-a

Upgrade all file systems on all imported pools.


filesystem

Upgrade the specified file system.


-r

Upgrade the specified file system and all descendent file systems


-V version

Upgrade to the specified version. If the -V flag is not specified,
this command upgrades to the most recent version. This option can only be used
to increase the version number, and only up to the most recent version
supported by this software.




zfs userspace [-Hinp] [-o field[,field]...]
[-s field]...
[-S field]...
[-t type[,type]...] filesystem|snapshot

Displays space consumed by, and quotas on, each user in the specified
filesystem or snapshot. This corresponds to the userused@user and
userquota@user properties.
-n

Print numeric ID instead of user/group name.


-H

Do not print headers, use tab-delimited output.


-p

Use exact (parsable) numeric output.


-o field[,field]...

Display only the specified fields from the following
set: type, name, used, quota. The default is to display all fields.


-s field

Sort output by this field. The s and S flags may be specified
multiple times to sort first by one field, then by another. The default is
-s type -s name.


-S field

Sort by this field in reverse order. See -s.


-t type[,type]...

Print only the specified types from the following
set: all, posixuser, smbuser, posixgroup, smbgroup. The default
is -t posixuser,smbuser. The default can be changed to include group
types.


-i

Translate SID to POSIX ID. The POSIX ID may be ephemeral if no mapping exists.
Normal POSIX interfaces (for example, stat(2), ls -l) perform
this translation, so the -i option allows the output from zfs
userspace to be compared directly with those utilities. However, -i
may lead to confusion if some files were created by an SMB user before a
SMB-to-POSIX name mapping was established. In such a case, some files will be owned
by the SMB entity and some by the POSIX entity. However, the -i option
will report that the POSIX entity has the total usage and quota for both.




zfs groupspace [-Hinp] [-o field[,field]...]
[-s field]...
[-S field]...
[-t type[,type]...] filesystem|snapshot

Displays space consumed by, and quotas on, each group in the specified
filesystem or snapshot. This subcommand is identical to zfs userspace,
except that the default types to display are -t posixgroup,smbgroup.


zfs mount

Displays all ZFS file systems currently mounted.


zfs mount [-vO] [-o options] -a |
filesystem

Mounts ZFS file systems. Invoked automatically as part of the boot
process.
-o options

An optional, comma-separated list of mount options to use temporarily for the
duration of the mount. See the "Temporary Mount Point Properties" section for
details.


-O

Perform an overlay mount. See mount(1M) for more information.


-v

Report mount progress.


-a

Mount all available ZFS file systems. Invoked automatically as part of
the boot process.


filesystem

Mount the specified filesystem.




zfs unmount [-f] -a | filesystem|mountpoint

Unmounts currently mounted ZFS file systems. Invoked automatically as
part of the shutdown process.
-f

Forcefully unmount the file system, even if it is currently in use.


-a

Unmount all available ZFS file systems. Invoked automatically as part of
the boot process.


filesystem|mountpoint

Unmount the specified filesystem. The command can also be given a path to a
ZFS file system mount point on the system.




zfs share -a | filesystem

Shares available ZFS file systems.
-a

Share all available ZFS file systems. Invoked automatically as part of
the boot process.


filesystem

Share the specified filesystem according to the sharenfs and
sharesmb properties. File systems are shared when the sharenfs or
sharesmb property is set.




zfs unshare -a | filesystem|mountpoint

Unshares currently shared ZFS file systems. This is invoked automatically
as part of the shutdown process.
-a

Unshare all available ZFS file systems. Invoked automatically as part of
the boot process.


filesystem|mountpoint

Unshare the specified filesystem. The command can also be given a path to a
ZFS file system shared on the system.




zfs send [-DnPpRv] [-[iI] snapshot] snapshot

Creates a stream representation of the second snapshot, which is written
to standard output. The output can be redirected to a file or to a different
system (for example, using ssh(1). By default, a full stream is
generated.
-i snapshot

Generate an incremental stream from the first snapshot to the second
snapshot. The incremental source (the first snapshot) can be
specified as the last component of the snapshot name (for example, the part
after the @), and it is assumed to be from the same file system as the
second snapshot.
If the destination is a clone, the source may be the origin snapshot, which
must be fully specified (for example, pool/fs@origin, not just
@origin).


-I snapshot

Generate a stream package that sends all intermediary snapshots from the first
snapshot to the second snapshot. For example, -I @a fs@d is similar to
-i @a fs@b; -i @b fs@c; -i @c fs@d. The incremental source snapshot may
be specified as with the -i option.


-R

Generate a replication stream package, which will replicate the specified
filesystem, and all descendent file systems, up to the named snapshot. When
received, all properties, snapshots, descendent file systems, and clones are
preserved.
If the -i or -I flags are used in conjunction with the -R
flag, an incremental replication stream is generated. The current values of
properties, and current snapshot and file system names are set when the stream
is received. If the -F flag is specified when this stream is received,
snapshots and file systems that do not exist on the sending side are destroyed.


-D

Generate a deduplicated stream. Blocks which would have been sent multiple
times in the send stream will only be sent once. The receiving system must
also support this feature to recieve a deduplicated stream. This flag can
be used regardless of the dataset's dedup property, but performance
will be much better if the filesystem uses a dedup-capable checksum (eg.
sha256).


-p

Include the dataset's properties in the stream. This flag is implicit when
-R is specified. The receiving system must also support this feature.


-n

Do a dry-run ("No-op") send. Do not generate any actual send data. This is
useful in conjunction with the -v or -P flags to determine what
data will be sent.


-P

Print machine-parsable verbose information about the stream package generated.


-v

Print verbose information about the stream package generated. This information
includes a per-second report of how much data has been sent.


The format of the stream is committed. You will be able to receive your streams
on future versions of ZFS.


zfs receive [-vnFu]
filesystem|volume|snapshot

zfs receive [-vnFu] [-d|-e] filesystem

Creates a snapshot whose contents are as specified in the stream provided on
standard input. If a full stream is received, then a new file system is created
as well. Streams are created using the zfs send subcommand, which by
default creates a full stream. zfs recv can be used as an alias for
zfs receive.
If an incremental stream is received, then the destination file system must
already exist, and its most recent snapshot must match the incremental stream's
source. For zvols, the destination device link is destroyed and
recreated, which means the zvol cannot be accessed during the
receive operation.
When a snapshot replication package stream that is generated by using the
zfs send -R command is received, any snapshots that do not exist
on the sending location are destroyed by using the zfs destroy -d
command.
The name of the snapshot (and file system, if a full stream is received) that
this subcommand creates depends on the argument type and the use of the
-d or -e options.
If the argument is a snapshot name, the specified snapshot is created. If
the argument is a file system or volume name, a snapshot with the same name as
the sent snapshot is created within the specified filesystem or
volume. If neither of the -d or -e options are specified,
the provided target snapshot name is used exactly as provided.
The -d and -e options cause the file system name of the target
snapshot to be determined by appending a portion of the sent snapshot's name to
the specified target filesystem. If the -d option is specified, all
but the first element of the sent snapshot's file system path (usually the
pool name) is used and any required intermediate file systems within the
specified one are created. If the -e option is specified, then only the
last element of the sent snapshot's file system name (i.e. the name of the
source file system itself) is used as the target file system name.
-d

Discard the first element of the sent snapshot's file system name, using
the remaining elements to determine the name of the target file system for
the new snapshot as described in the paragraph above.


-e

Discard all but the last element of the sent snapshot's file system name,
using that element to determine the name of the target file system for
the new snapshot as described in the paragraph above.


-u

File system that is associated with the received stream is not mounted.


-v

Print verbose information about the stream and the time required to perform the
receive operation.


-n

Do not actually receive the stream. This can be useful in conjunction with the
-v option to verify the name the receive operation would use.


-F

Force a rollback of the file system to the most recent snapshot before
performing the receive operation. If receiving an incremental replication
stream (for example, one generated by zfs send -R -[iI]), destroy
snapshots and file systems that do not exist on the sending side.




zfs allow filesystem | volume

Displays permissions that have been delegated on the specified filesystem or
volume. See the other forms of zfs allow for more information.


zfs allow [-ldug] user|group[,user|group]...
perm|@setname[,perm|@setname]... filesystem|volume

zfs allow [-ld] -e|everyone perm|@setname[,perm|@setname]...
filesystem|volume

Delegates ZFS administration permission for the file systems to
non-privileged users.
[-ug] user|group[,user|group]...

Specifies to whom the permissions are delegated. Multiple entities can be
specified as a comma-separated list. If neither of the -ug options are
specified, then the argument is interpreted preferentially as the keyword
everyone, then as a user name, and lastly as a group name. To specify a user
or group named "everyone", use the -u or -g options. To specify a
group with the same name as a user, use the -g options.


-e|everyone

Specifies that the permissions be delegated to everyone.


perm|@setname[,perm|@setname]...

The permissions to delegate. Multiple permissions
may be specified as a comma-separated list. Permission names are the same as
ZFS subcommand and property names. See the property list below. Property
set names, which begin with an at sign (@) , may be specified. See the
-s form below for details.


[-ld] filesystem|volume

Specifies where the permissions are delegated. If neither of the -ld
options are specified, or both are, then the permissions are allowed for the
file system or volume, and all of its descendents. If only the -l option
is used, then is allowed "locally" only for the specified file system. If only
the -d option is used, then is allowed only for the descendent file
systems.





Permissions are generally the ability to use a ZFS subcommand or change a
ZFS property. The following permissions are available:
NAME TYPE NOTES
allow subcommand Must also have the permission that is being
 allowed
clone subcommand Must also have the 'create' ability and 'mount'
 ability in the origin file system
create subcommand Must also have the 'mount' ability
destroy subcommand Must also have the 'mount' ability
diff subcommand Allows lookup of paths within a dataset
 given an object number, and the ability to
 create snapshots necessary to 'zfs diff'.
mount subcommand Allows mount/umount of ZFS datasets
promote subcommand Must also have the 'mount'
 and 'promote' ability in the origin file system
receive subcommand Must also have the 'mount' and 'create' ability
rename subcommand Must also have the 'mount' and 'create'
 ability in the new parent
rollback subcommand Must also have the 'mount' ability
send subcommand
share subcommand Allows sharing file systems over NFS or SMB
 protocols
snapshot subcommand Must also have the 'mount' ability
groupquota other Allows accessing any groupquota@... property
groupused other Allows reading any groupused@... property
userprop other Allows changing any user property
userquota other Allows accessing any userquota@... property
userused other Allows reading any userused@... property

aclinherit property
aclmode property
atime property
canmount property
casesensitivity property
checksum property
compression property
copies property
devices property
exec property
mountpoint property
nbmand property
normalization property
primarycache property
quota property
readonly property
recordsize property
refquota property
refreservation property
reservation property
secondarycache property
setuid property
shareiscsi property
sharenfs property
sharesmb property
snapdir property
utf8only property
version property
volblocksize property
volsize property
vscan property
xattr property
zoned property


zfs allow -c perm|@setname[,perm|@setname]...
filesystem|volume

Sets "create time" permissions. These permissions are granted (locally) to the
creator of any newly-created descendent file system.


zfs allow -s @setname perm|@setname[,perm|@setname]...
filesystem|volume

Defines or adds permissions to a permission set. The set can be used by other
zfs allow commands for the specified file system and its descendents.
Sets are evaluated dynamically, so changes to a set are immediately reflected.
Permission sets follow the same naming restrictions as ZFS file systems, but
the name must begin with an "at sign" (@), and can be no more than 64
characters long.


zfs unallow [-rldug] user|group[,user|group]...
[perm|@setname[,perm|@setname]...] filesystem|volume

zfs unallow [-rld] -e|everyone [perm|@setname[,perm|@setname]...]
filesystem|volume

zfs unallow [-r] -c [perm|@setname[,perm|@setname]...]

filesystem|volume

Removes permissions that were granted with the zfs allow command. No
permissions are explicitly denied, so other permissions granted are still in
effect. For example, if the permission is granted by an ancestor. If no
permissions are specified, then all permissions for the specified user,
group, or everyone are removed. Specifying everyone (or using the
-e option) only removes the permissions that were granted to everyone,
not all permissions for every user and group. See the zfs allow command
for a description of the -ldugec options.
-r

Recursively remove the permissions from this file system and all descendents.




zfs unallow [-r] -s @setname
[perm|@setname[,perm|@setname]...]

filesystem|volume

Removes permissions from a permission set. If no permissions are specified,
then all permissions are removed, thus removing the set entirely.


zfs hold [-r] tag snapshot...

Adds a single reference, named with the tag argument, to the specified
snapshot or snapshots. Each snapshot has its own tag namespace, and tags must
be unique within that space.
If a hold exists on a snapshot, attempts to destroy that snapshot by using the
zfs destroy command return EBUSY.
-r

Specifies that a hold with the given tag is applied recursively to the
snapshots of all descendent file systems.




zfs holds [-r] snapshot...

Lists all existing user references for the given snapshot or snapshots.
-r

Lists the holds that are set on the named descendent snapshots, in addition to
listing the holds on the named snapshot.




zfs release [-r] tag snapshot...

Removes a single reference, named with the tag argument, from the
specified snapshot or snapshots. The tag must already exist for each snapshot.
If a hold exists on a snapshot, attempts to destroy that snapshot by using the
zfs destroy command return EBUSY.
-r

Recursively releases a hold with the given tag on the snapshots of all
descendent file systems.


zfs diff [-FHt] snapshot snapshot|filesystem

Display the difference between a snapshot of a given filesystem and another
snapshot of that filesystem from a later time or the current contents of the
filesystem. The first column is a character indicating the type of change,
the other columns indicate pathname, new pathname (in case of rename), change
in link count, and optionally file type and/or change time.

The types of change are:
- The path has been removed
+ The path has been created
M The path has been modified
R The path has been renamed

-F

Display an indication of the type of file, in a manner similar to the -F
option of ls(1).
B Block device
C Character device
/ Directory
> Door
| Named pipe
@ Symbolic link
P Event port
= Socket
F Regular file


-H

Give more parseable tab-separated output, without header lines and without arrows.

-t

Display the path's inode change time as the first column of output.


 EXAMPLES

Example 1 Creating a ZFS File System Hierarchy

The following commands create a file system named pool/home and a file
system named pool/home/bob. The mount point /export/home is set for
the parent file system, and is automatically inherited by the child file
system.

# zfs create pool/home
# zfs set mountpoint=/export/home pool/home
# zfs create pool/home/bob



Example 2 Creating a ZFS Snapshot

The following command creates a snapshot named yesterday. This snapshot
is mounted on demand in the .zfs/snapshot directory at the root of the
pool/home/bob file system.

# zfs snapshot pool/home/bob@yesterday



Example 3 Creating and Destroying Multiple Snapshots

The following command creates snapshots named yesterday of
pool/home and all of its descendent file systems. Each snapshot is
mounted on demand in the .zfs/snapshot directory at the root of its
file system. The second command destroys the newly created snapshots.

# zfs snapshot -r pool/home@yesterday
# zfs destroy -r pool/home@yesterday



Example 4 Disabling and Enabling File System Compression

The following command disables the compression property for all file
systems under pool/home. The next command explicitly enables
compression for pool/home/anne.

# zfs set compression=off pool/home
# zfs set compression=on pool/home/anne



Example 5 Listing ZFS Datasets

The following command lists all active file systems and volumes in the system.
Snapshots are displayed if the listsnaps property is on. The
default is off. See zpool(1M) for more information on pool
properties.

# zfs list
 NAME USED AVAIL REFER MOUNTPOINT
 pool 450K 457G 18K /pool
 pool/home 315K 457G 21K /export/home
 pool/home/anne 18K 457G 18K /export/home/anne
 pool/home/bob 276K 457G 276K /export/home/bob



Example 6 Setting a Quota on a ZFS File System

The following command sets a quota of 50 Gbytes for pool/home/bob.

# zfs set quota=50G pool/home/bob



Example 7 Listing ZFS Properties

The following command lists all properties for pool/home/bob.

# zfs get all pool/home/bob
NAME PROPERTY VALUE SOURCE
pool/home/bob type filesystem -
pool/home/bob creation Tue Jul 21 15:53 2009 -
pool/home/bob used 21K -
pool/home/bob available 20.0G -
pool/home/bob referenced 21K -
pool/home/bob compressratio 1.00x -
pool/home/bob mounted yes -
pool/home/bob quota 20G local
pool/home/bob reservation none default
pool/home/bob recordsize 128K default
pool/home/bob mountpoint /pool/home/bob default
pool/home/bob sharenfs off default
pool/home/bob checksum on default
pool/home/bob compression on local
pool/home/bob atime on default
pool/home/bob devices on default
pool/home/bob exec on default
pool/home/bob setuid on default
pool/home/bob readonly off default
pool/home/bob zoned off default
pool/home/bob snapdir hidden default
pool/home/bob aclmode discard default
pool/home/bob aclinherit restricted default
pool/home/bob canmount on default
pool/home/bob shareiscsi off default
pool/home/bob xattr on default
pool/home/bob copies 1 default
pool/home/bob version 4 -
pool/home/bob utf8only off -
pool/home/bob normalization none -
pool/home/bob casesensitivity sensitive -
pool/home/bob vscan off default
pool/home/bob nbmand off default
pool/home/bob sharesmb off default
pool/home/bob refquota none default
pool/home/bob refreservation none default
pool/home/bob primarycache all default
pool/home/bob secondarycache all default
pool/home/bob usedbysnapshots 0 -
pool/home/bob usedbydataset 21K -
pool/home/bob usedbychildren 0 -
pool/home/bob usedbyrefreservation 0 -



The following command gets a single property value.

# zfs get -H -o value compression pool/home/bob
on



The following command lists all properties with local settings for
pool/home/bob.

# zfs get -r -s local -o name,property,value all pool/home/bob
NAME PROPERTY VALUE
pool/home/bob quota 20G
pool/home/bob compression on



Example 8 Rolling Back a ZFS File System

The following command reverts the contents of pool/home/anne to the
snapshot named yesterday, deleting all intermediate snapshots.

# zfs rollback -r pool/home/anne@yesterday



Example 9 Creating a ZFS Clone

The following command creates a writable file system whose initial contents are
the same as pool/home/bob@yesterday.

# zfs clone pool/home/bob@yesterday pool/clone



Example 10 Promoting a ZFS Clone

The following commands illustrate how to test out changes to a file system, and
then replace the original file system with the changed one, using clones, clone
promotion, and renaming:

# zfs create pool/project/production
 populate /pool/project/production with data
# zfs snapshot pool/project/production@today
# zfs clone pool/project/production@today pool/project/beta
make changes to /pool/project/beta and test them
# zfs promote pool/project/beta
# zfs rename pool/project/production pool/project/legacy
# zfs rename pool/project/beta pool/project/production
once the legacy version is no longer needed, it can be destroyed
# zfs destroy pool/project/legacy



Example 11 Inheriting ZFS Properties

The following command causes pool/home/bob and pool/home/anne to
inherit the checksum property from their parent.

# zfs inherit checksum pool/home/bob pool/home/anne



Example 12 Remotely Replicating ZFS Data

The following commands send a full stream and then an incremental stream to a
remote machine, restoring them into poolB/received/fs@aand
poolB/received/fs@b, respectively. poolB must contain the file
system poolB/received, and must not initially contain
poolB/received/fs.

# zfs send pool/fs@a | \e
 ssh host zfs receive poolB/received/fs@a
# zfs send -i a pool/fs@b | ssh host \e
 zfs receive poolB/received/fs



Example 13 Using the zfs receive -d Option

The following command sends a full stream of poolA/fsA/fsB@snap to a
remote machine, receiving it into poolB/received/fsA/fsB@snap. The
fsA/fsB@snap portion of the received snapshot's name is determined from
the name of the sent snapshot. poolB must contain the file system
poolB/received. If poolB/received/fsA does not exist, it is created
as an empty file system.

# zfs send poolA/fsA/fsB@snap | \e
 ssh host zfs receive -d poolB/received



Example 14 Setting User Properties

The following example sets the user-defined com.example:department
property for a dataset.

# zfs set com.example:department=12345 tank/accounting



Example 15 Creating a ZFS Volume as an iSCSI Target Device

The following example shows how to create a ZFS volume as an iSCSI
target.

# zfs create -V 2g pool/volumes/vol1
# zfs set shareiscsi=on pool/volumes/vol1
# iscsitadm list target
Target: pool/volumes/vol1
 iSCSI Name:
 iqn.1986-03.com.sun:02:7b4b02a6-3277-eb1b-e686-a24762c52a8c
 Connections: 0



After the iSCSI target is created, set up the iSCSI initiator. For
more information about the Solaris iSCSI initiator, see
iscsitadm(1M).

Example 16 Performing a Rolling Snapshot

The following example shows how to maintain a history of snapshots with a
consistent naming scheme. To keep a week's worth of snapshots, the user
destroys the oldest snapshot, renames the remaining snapshots, and then creates
a new snapshot, as follows:

# zfs destroy -r pool/users@7daysago
# zfs rename -r pool/users@6daysago @7daysago
# zfs rename -r pool/users@5daysago @6daysago
# zfs rename -r pool/users@yesterday @5daysago
# zfs rename -r pool/users@yesterday @4daysago
# zfs rename -r pool/users@yesterday @3daysago
# zfs rename -r pool/users@yesterday @2daysago
# zfs rename -r pool/users@today @yesterday
# zfs snapshot -r pool/users@today



Example 17 Setting sharenfs Property Options on a ZFS File System

The following commands show how to set sharenfs property options to
enable rw access for a set of IP addresses and to enable root
access for system neo on the tank/home file system.

# zfs set sharenfs='rw=@123.123.0.0/16,root=neo' tank/home



If you are using DNS for host name resolution, specify the fully
qualified hostname.


Example 18 Delegating ZFS Administration Permissions on a ZFS Dataset

The following example shows how to set permissions so that user cindys
can create, destroy, mount, and take snapshots on tank/cindys. The
permissions on tank/cindys are also displayed.

# zfs allow cindys create,destroy,mount,snapshot tank/cindys
# zfs allow tank/cindys
-------------------------------------------------------------
Local+Descendent permissions on (tank/cindys)
 user cindys create,destroy,mount,snapshot
-------------------------------------------------------------



Because the tank/cindys mount point permission is set to 755 by default,
user cindys will be unable to mount file systems under tank/cindys.
Set an ACL similar to the following syntax to provide mount point access:
# chmod A+user:cindys:add_subdirectory:allow /tank/cindys



Example 19 Delegating Create Time Permissions on a ZFS Dataset

The following example shows how to grant anyone in the group staff to
create file systems in tank/users. This syntax also allows staff members
to destroy their own file systems, but not destroy anyone else's file system.
The permissions on tank/users are also displayed.

# zfs allow staff create,mount tank/users
# zfs allow -c destroy tank/users
# zfs allow tank/users
-------------------------------------------------------------
Create time permissions on (tank/users)
 create,destroy
Local+Descendent permissions on (tank/users)
 group staff create,mount
-------------------------------------------------------------



Example 20 Defining and Granting a Permission Set on a ZFS Dataset

The following example shows how to define and grant a permission set on the
tank/users file system. The permissions on tank/users are also
displayed.

# zfs allow -s @pset create,destroy,snapshot,mount tank/users
# zfs allow staff @pset tank/users
# zfs allow tank/users
-------------------------------------------------------------
Permission sets on (tank/users)
 @pset create,destroy,mount,snapshot
Create time permissions on (tank/users)
 create,destroy
Local+Descendent permissions on (tank/users)
 group staff @pset,create,mount
-------------------------------------------------------------



Example 21 Delegating Property Permissions on a ZFS Dataset

The following example shows to grant the ability to set quotas and reservations
on the users/home file system. The permissions on users/home are
also displayed.

# zfs allow cindys quota,reservation users/home
# zfs allow users/home
-------------------------------------------------------------
Local+Descendent permissions on (users/home)
 user cindys quota,reservation
-------------------------------------------------------------
cindys% zfs set quota=10G users/home/marks
cindys% zfs get quota users/home/marks
NAME PROPERTY VALUE SOURCE
users/home/marks quota 10G local



Example 22 Removing ZFS Delegated Permissions on a ZFS Dataset

The following example shows how to remove the snapshot permission from the
staff group on the tank/users file system. The permissions on
tank/users are also displayed.

# zfs unallow staff snapshot tank/users
# zfs allow tank/users
-------------------------------------------------------------
Permission sets on (tank/users)
 @pset create,destroy,mount,snapshot
Create time permissions on (tank/users)
 create,destroy
Local+Descendent permissions on (tank/users)
 group staff @pset,create,mount
-------------------------------------------------------------



Example 23 Showing the differences between a snapshot and a ZFS Dataset

The following example shows how to see what has changed between a prior
snapshot of a ZFS Dataset and its current state. The -F option is used
to indicate type information for the files affected.

# zfs diff -F tank/test@before tank/test
M / /tank/test/
M F /tank/test/linked (+1)
R F /tank/test/oldname -> /tank/test/newname
- F /tank/test/deleted
+ F /tank/test/created
M F /tank/test/modified


 EXIT STATUS

The following exit values are returned:
0

Successful completion.


1

An error occurred.


2

Invalid command line options were specified.


 ATTRIBUTES

See attributes(5) for descriptions of the following attributes:




ATTRIBUTE TYPE ATTRIBUTE VALUE
Interface Stability Committed


 SEE ALSO

ssh(1), iscsitadm(1M), mount(1M), share(1M),
sharemgr(1M), unshare(1M), zonecfg(1M), zpool(1M),
chmod(2), stat(2), write(2), fsync(3C),
dfstab(4), acl(5), attributes(5)

See the gzip(1) man page, which is not part of the SunOS man page
collection.

For information about using the ZFS web-based management tool and other
ZFS features, see the Solaris ZFS Administration Guide.